target: Don't return success from module_init() if setup fails

If the call to core_dev_release_virtual_lun0() fails, then nothing
sets ret to anything other than 0, so even though everything is
torn down and freed, target_core_init_configfs() will seem to succeed
and the module will be loaded.  Fix this by passing the return value
on up the chain.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_configfs.c

@@ -3206,7 +3206,8 @@ static int __init target_core_init_configfs(void)
 	if (ret < 0)
 		goto out;
 
-	if (core_dev_setup_virtual_lun0() < 0)
+	ret = core_dev_setup_virtual_lun0();
+	if (ret < 0)
 		goto out;
 
 	return 0;